Due to the characteristics of flexible size and strong environmental adaptability, an LED display screen is widely applied in the field of media. At present, LED display devices universally used in a market are generally of black box body type, lamp bar screen and grid screen type structures and strip structure. In some special occasions, environments such as glass curtain walls, shopwindows, stage backgrounds, emporiums, hotels, airports and the like need an LED display module to be high in permeability and good in daylighting and light transmission effects and also keep certain pixel density at the same time; while the LED display devices of the black box body type, lamp bar screen and grid screen type structures cannot be coordinated with peripheral using environments. For example, if the box body type LED display devices are installed on the glass curtain walls and background walls, light may be completely blocked, and the light transmittance effect is lost; lamp bar screens and grid screens are difficult to satisfy glass curtain wall structures of various sizes; if the using cost is greatly increased, it is very inconvenient for later maintenance; and the strip LED display screens are formed as follows: LED light-emitting units are installed on strip circuit boards and fixed by a non-transparent housing, a plurality of such lamp bars form a unit module, and a plurality of unit modules are cascaded to form a display screen. Because the non-transparent housing occupies a larger space, certain light transmittance effect may be provided only when a pixel pitch between two unit modules is above 40 mm, but the display screen is not suitable for an application occasion with a smaller watching distance if the pixel pitch is too large. Meanwhile, because it is apparent that the strip structure of such non-transparent display module may bring people a bounding feeling whether installed indoors or outdoors and is not suitable for high-grade application occasions such as the shopwindows, emporium glass curtain walls and the like, the market calls for the LED display screen with high pixel density and high permeability.